3-4 of the same type.

4 of the same time offhand gathers. Harvest>Harvest>Harvest>Harvest
or
toss in at least 1 mainhand.
Quarry>Quarry>Mine works or Mine>Mine>Quarry etc.

You could still reasonably spearfish probably since there's usually at least 2 spearfishing and 2 schools in a area.